1,721,011 research outputs found
Retinoids and human breast cancer: in vivo effects of an antagonist for RAR-a.
No full textThe aim of the present study was to evaluate the in vivo effects of the RAR-a selective antagonist Ro 41-5253 on a xenograft
animal model for breast cancer. Our observations indicate a lack of toxic side effects of the drug, even when used at high
dosages. It is interesting to note that using Ro 41-5253 at dosages of 10, 30 and 100 mg/kg/die resulted in a slight, but significant
inhibition of cell growth. The data obtained in this study represents the basis for a further evaluation of Ro 41-5253
anti-neoplastic activity on transgenic breast cancer animal models.
q 2004 Elsevier Ireland Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Histone deacetylase Inhibitors enhance retinoid response in human breast cancer cell lines
No full textSolid tumors develop resistance to retinoids during
carcinogenesis. One of the strategies to overcome this
resistance may include the combination of these molecules
with other differentiating, cytotoxic or chromatin-remodelling
agents. We analysed the anti-proliferative activity of two
histone-deacetylase inhibitors (HDACIs), Trichostatin A
(TSA) and Sodium Phenylbutyrate (PB), alone or combined
with retinoids, all-trans retinoic acid (ATRA) and Ro 41-5253,
on two human breast cancer cell lines: the hormone-dependent
MCF-7 and the hormone-independent MDA-MB-231. These
lines responded differently to retinoids: MCF-7 were sensitive,
whilst MDA-MB-231 were rather resistant. When the retinoids
were combined with HDACIs, these molecules potentiated the
retinoid activity on growth inhibition, especially for the
association Ro 41-5253 and TSA. By FACS analysis we
observed that the anti-proliferative effects were only partially
due to pro-apopotic mechanisms, suggesting a cell-cycle block.
The efficacy of the retinoids/HDACIs combinations could
represent a new strategy in breast cancer chemotherapy,
allowing inhibition of both ER+ and ER- cell populations
Modifications of nuclear architecture and chromatin organization in ataxia telangiectasia cells are coupled to changes of gene transcription
No full textAtaxia telangiectasia (AT) is a rare genetic disorder caused by mutations of ATM gene. ATM kinase is a "master controller" of DNA-damage response and signal transducer of external stimuli. The complex role of ATM may explain the pleiotropic phenotype characteristic of AT syndrome, only partially. In our hypothesis, the multi-faceted phenotype of AT patients might depend on specific chromatin reorganization, which then reflects on the cellular transcription. We analyzed three lymphoblastoid cell-lines isolated from AT patients and one healthy control. The three-dimensional reconstruction disclosed marked changes of nuclear morphology and architecture in AT cells. When chromatin condensation was analyzed by differential scanning calorimetry, a remodeling was observed at the level of fiber folding and nucleosome conformation. Despite the structural differences, chromatin did not exhibit modifications of the average acetylation status in comparison to the control. Moreover, AT cells presented significant alterations in the transcription of genes involved in cell-cycle regulation and stress response. In AT3RM cells, the average chromatin decondensation went with the upregulation of c-fos, c-jun, and c-myc and downregulation of metallothioneins, p21 and p53. AT9RM and AT44RM cells were instead characterized by an increased chromatin condensation and presented a different transcription unbalance. Whereas in AT44RM all the considered genes were downregulated, in AT3RM the three oncogenes and metallothioneins were upregulated, but p53 and p21 were downregulated
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Synergistic effect of the anti-HER-2/neu antibody and cisplatin in immortalized and primary mesothelioma cell lines
No full textMalignant mesothelioma (MM) still remains a therapeutic and diagnostic problem to which new therapeutic perspectives are being continuously tried and tested. Three different primary cultures (MMGe-1, MES MM 98, and MES 1) and one immortalized cell line (MSTO 211 H) of human MM were studied in order to evaluate the HER-2/neu expression. Three out of four cell lines showed a different level of c-erbB-2 expression, the highest being detected on the MSTO 211 H cell line (fibroblastic phenotype), whereas MMGe-1 resulted negative. The effect of the anti-HER-2/neu antibody (Trastuzumab) alone, and in combination with cisplatin (CDDP) at different doses (ranging from 0.1 to 100 100 μg/ml), was studied on all the c-erB-2 positive cell lines. Trastuzumab was able to inhibit cell proliferation in a time-dependent manner, with growth inhibition also obtained at low concentrations (0.1 - 1 μg/ml). Combined treatment with Trastuzumab (10 μg/ml) and CDDP (1 μg/ml) showed synergism. Our results were encouraging, and suggest a rationale for further investigations in a clinical setting. © 2002 Wiley-Liss, Inc
4-OH Tamoxifen does not interfere with Bicalutamide inhibitory effects on human prostatic cancer cells in vitro.
No full textDispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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